Automobile clutch



Feb. 7, 1939. .w s, WOLFRAM 2,146,042

'AUTOMOBILE CLUTCH Fledy July 8, 1937 www ,652g 3 v @www2/fwd@- Patented Feb.7,1939

UNITED STATES PATENT oFFlcE AUTOMOBILE CLUTCH William S. Wolfram, Dayton,l Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application July 8, 1937, Serial No. 152,473

4 Claims.

This invention relates to friction clutches and in particular to such a clutch as is used between the engine of a motor vehicle and the input shaft of the change speed transmission.

An object of the invention is to provide for a gradual application of the load when the engaging elements of the clutch come into frictional contact.

A more specific object is to provide an improved driven member adapted for use in an otherwise conventional clutch.

Still further, the clutch makes use of a resilient means opposing the action of the main clutch spring, this `resilient means operable to cause a gradual clutch engagement and the construction so locates the resilient means that it shall be subjected as little as possible :to the heat developed by the friction incident to the engagement of the clutch members.

Other objects and advantages will be understood from the following description.

In the drawing:

Figure 1 is a transverse section through the improved clutch.

Figure 2 shows the driven member in elevation.

Figure 3 is a section on line 3-3 of Figure 2.

vFigure 4 is a section on line 4-4 of Figure 2.

Numerals of reference are used on the drawing as follows:

Numeral 1 shows the housing for the clutch by which the engine crankshaft 3 drives the\ input shaft I leading to the change speed transmission not shown.

Numeral I3 is one of the fastening means for securing the flywheel I5 to the crankshaft. Fastening means l1 serve to secure to the ywheel a cover I9, this cover acting as an abutment for springs 2| operable to push a pressure plate 23 toward the flywheel and grip the driven member therebetween.

A more or lss conventional releasing means is illustrated. The pressure plate has a plurality of projecting lugs extending through openings 21 of the cover plate. Threaded into these lugs are members 25, the rounded ends of which are adapted to be engaged by similarly shaped ends of levers or fingers 29, the latter fulcrumed on driven plate is provided with a friction clutch facing 43 secured thereto on the side adjacent the flywheel by rivets 45. A second spring steel plate 41 has a facing 49 secured thereto by rivets 5I, this facing being on the side of plate 41 ad- I jacent the pressure plate. This second plate has a plurality of radial slots 53 extending from its inner peripheral margin 55 to circular holes 51 located radially within the region of the facing. shouldered rivets 59 are secured to the driven 10 plate'4l and extend freely through the holes 51 and have heads 6I whereby the plate 41 may move to and fro axially relative to the driven plate but is held from separation therefrom by the heads SI. The slots 53 form spring arms marked on the 15 drawing by numeral 63. The inner ends of these arms engage a radially extended part of the flange 31. The plates 4I and 41 are spaced apart as shown in Figures 3 and 4 when the clutch has been released by the action of the fingers or levers 29. In this relation of parts the plate 41 is held by the rivet heads 6I and its inner spring arms engage the part 65 on the hub. These spring arms are then substantially at and parallel with the driven plate. When the clutch pedal is released 25 and springs 2| allowed to operate, the pressure plate moves toward the flywheel and pushes plate 41 against plate 4|. In so doing the part of plate 41 embracing the rivets 59 moves away from the heads 6| as will be seen by comparing Figure 3 80 with Figure 1. Also the spring fingers 63 are distorted to the shape shown in Figure 1 owing to their engagement with part 65 on the hub. 'I'his bowing ofthe spring fingers oiers sufficient resilient resistance to the action of springs 2| to 35 insure a gradual engagement of the clutch members. Itv also constitutes a resilient potential energy to effect the separation of member 41 from 4| when the clutch is released. The location of these 'resilient fingers radially within the region 40 of frictional engagement removes them from the influence vof the heat generated by the frictional contact of the clutch members.

I claim: *e 1. In a friction clutch, spaced driving members 45 having relative axial movement and a driven member adapted to be gripped therebetween, said driven member comprising a hub, a driven plate secured thereto, a second plate, means carried by the driven plate whereby said second plate rotates 50 with the driven plate and has limited axial movement relative thereto, said second plate having a central opening disconnectedly surrounding .a rst part of said hub, said hub having a second part axially spaced from the first part and exl tending radially from, said hub, said second plate adapted to engage said second part and be flexed thereby when the two plates are gripped between said driving members. l

2. 'Ihe invention defined by claim 1, said rst named means comprising shouldered and headed rivets secured to said driven plate, said second plate slidable on said rivets and engageable with the heads thereof.

3. In a friction clutch, spaced driving members having relative axial movement and a driven member adapted to be gripped therebetween, said driven member comprising a hub, a driven plate secured thereto, a second plate, means carried by the driven plate whereby said second plate rotates with the driven plate and has limited axial movement relative thereto, other means on said hub adapted to engage said second plate and cause it to be flexed when the two\p1ates are gripped between said driving members, said second plate formed with spring arms extending radially from said hub.

4. In a friction "clutch, spaced annular driving members having relative axial movement, a driven member adapted to be gripped between said driving members, said driven member comprising a central hub, a driven plate secured thereto and extending between said driving members, a second plate parallel to said driven plate and also ex.

tending between said driven members, a circular series of headed and shouldered rivets on said driven plate, said second plate slidable axially on said rivets and adapted to engage the heads thereof, said second plate having spring arms extending radially from said shouldered rivets ment.

WILLIAM S. WOLFRAM. 

